This study involves the development of thin oral solvent cast films for the potential delivery of the proton pump inhibitor, omeprazole (OME) via the buccal mucosa for paediatric patients. OME containing films were prepared from ethanolic gels (1% w/w) of metolose (MET) with polyethylene glycol (PEG 400) (0.5% w/w) as plasticiser, and L-arginine (l-arg) (0.2% w/w) as a stabilizer and dried in an oven at 40 °C. The blank and drug loaded films were divided into two groups, one group was subjected to supercritical carbon dioxide (scCO2) treatment and the other group untreated. The untreated and scCO2 treated films were then characterised using differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, hydration (swelling), mucoadhesion and in vitro drug dissolution studies. Treatment of the solvent cast films with scCO2 caused significant changes to the functional and physical properties of the MET films. The original drug loaded MET films showed a sustained release of OME (1 h), whereas scCO2 treatment of the formulations resulted in fast dissolving films with > 90% drug release within 15 min.